The Cancer Prevention, Control, and Population Sciences Career Development Award is requested to support the career development of Dr. Julie Britton, who is a classically trained cancer epidemiologist. The primary aim of the K07 grant is to position Dr. Britton as an independent research scientist specializing in relationships between energy balance and cancer risk. The research aims-relating energy balance to breast cancer risk- will be examined in a large case-control study of breast cancer among African American women in New York City. Traditional chronic disease epidemiology focuses on single risk factor-disease associations at the individual level with little consideration of their biological or social context, an approach that is often referred to as "black box" epidemiology. Dr. Britton's career goal is to advance beyond the "black box" that currently obscures relationships between energy balance and cancer risk. Her training program will enable her to acquire in-depth knowledge of the three energy balance components (body size characteristics, diet, and physical activity), better understanding of the physiological basis of energy balance, and proficiency in the essential statistical techniques necessary to incorporate all three risk components into an analytic model. In addition, training will address conducting and translating research in minority populations. The training program includes an internship, graduate coursework, and attendance at carefully chosen symposia and national meetings. Dr. Britton's proposal is sponsored by Drs. Mary Wolff and Christine Ambrosone (molecular epidemiology) and Dr. Larry Kushi (nutritional epidemiology). Additional advisors in two highly specialized areas of energy balance will be Drs. Steven Heymsfield (characteristics of body size) and Leslie Bernstein (physical activity and reproductive cancers). Body size characteristics, dietary intake, and physical activity have been associated with breast cancer risk among Caucasian women. These energy balance components are also strongly suspected to be risk factors for the disease in African American women. However, despite steadily increasing rates of incidence and mortality from breast cancer, research is sparse among African Americans. Results of the proposed research project will be of enormous public health relevance since they may advance our knowledge of modifiable breast cancer risk factors among a high-risk group of women, thereby providing information that is essential for primary prevention.